Bridging the timing gap: connecting Southern Ocean and Antarctic Climate records

Lead Research Organisation: University of Bristol
Department Name: Earth Sciences

Abstract

In light of current concerns over greenhouse-gas emissions and related temperature rise it is important to understand the mechanisms operating in the global climate system. This understanding may allow us to anticipate human-induced climate change and related ecosystem vulnerability. The Southern Ocean plays a central role in defining Earth's climate because it is a location where cold, deep waters rise to the surface and exchange gases and heat with the atmosphere. One of the most important gases for the climate system is carbon dioxide (CO2). Since the oceans contain about 60 times more carbon than the atmosphere, it only takes a small perturbation in the ocean to have a large climate impact. Atmospheric CO2 levels have shown systematic changes over the past 800,000 years as revealed by gasses trapped in ice cores, and recent evidence has come to light that shows that CO2 can increase rapidly over only hundreds of years. We still do not know how and why these changes in CO2 occur but their size and speed suggests that they must have been driven by changes in the deep ocean.

Mechanisms that have been put forward to explain lower atmospheric CO2 concentrations during past cold (glacial) periods focus on increased CO2 uptake in the Southern Ocean. This could have been achieved by a combination of increased sea ice cover and a more layered structure in the water column, which prevents CO2 from escaping to the atmosphere. The concept is supported by modeling evidence and predicts that we should find old, carbon-rich waters in the deep Southern Ocean during past cold times. If this layered water structure was removed, then these deep waters would release CO2 to the atmosphere as ice ages came to a close. Records from ice cores show us that the actual rise of CO2 during the end of the last ice age ('last deglaciation') happened in multiple steps. So far, however, it has been very difficult to obtain records from the Southern Ocean to test the hypothesis posed above, or the alternative hypothesis that carbon sequestration in the South was achieved due to more active CO2 uptake by planktonic marine plants. What we have been lacking is a suitable recorder ('archive') of past environmental conditions directly in the Southern Ocean that can resolve time increments of about 100 years or less, similar to in the record preserved in ice cores.

With our project we aim to transform understanding of the Southern Ocean's role in climate change by creating detailed records of the circulation, temperature, and CO2 chemistry of the Southern Ocean at the end of the last ice age and into the current warm period (past 25,000 years) at unprecedented temporal resolution. To achieve this we will make geochemical measurements on the skeletons of fossil deep-sea corals, a novel archive that allows us to create unique coupled records of past oceanographic change on a precise and accurate timescale. The skeletons of deep-sea corals are formed using the chemical ingredients of the seawater that they live in. This means that during the lifetime of a coral (~100 years) a record of water mass composition and temperature is captured as they grow. By performing a suite of geochemical measurements on each fossil coral, we can reconstruct environmental conditions at the time it grew. Repeating this exercise for hundreds of corals will allow us to construct the first directly dated record of the Southern Ocean's behavior since the last ice age. Our new record will allow comparison of the relative timing of environmental changes in the Southern Ocean with those of ice core records. It will therefore address one of the most hotly debated questions in global climate change research, the origin of changes in atmospheric CO2 and temperature on time scales of hundreds to thousands of years.

Planned Impact

Beyond the scientific community, we have identified six end-user groups.


a) Secondary school students and teachers - a new workshop on the ocean's role in climate change delivered to schools through GeoBus: GeoBus is a highly successful educational outreach program developed and run by the Department of Earth & Environmental Sciences at the University of St Andrews. Climate-focused workshops are of particular interest to teachers and students, given the presence of climate science (and skeptics) in the media and news. We propose to deliver a workshop for secondary schools on climate change to be taught in Chemistry and Physics class slots, which will engage pupils in STEM subjects.


b) Policy makers - improved understanding of a key region for global climate that will help inform the IPCC: Over the last 10 years the Intergovernmental Panel on Climate Change (IPCC) has developed an increasing emphasis on the role of palaeoclimate to inform policymakers on how the climate system can operate. Our work will inform the next IPCC report thereby have a lasting benefit to a wide community of policy forming bodies, who require improved projections of the path of atmospheric CO2 rise and associated climate change, ocean acidification, and ecosystem change. The investigators of this proposal will furthermore commit to visiting each of their local MPs to establish a link for these decision makers to climate science.


c) General Public - Project Website and Public Lectures and Events: Significant action on climate change is likely only to be achieved with a groundswell of public understanding and concern. Our project provides an excellent teaching opportunity for public engagement with CO2 rise and associated climate change. This effort will be linked with existing and new outreach websites. We will also publicize our research through Facebook and Twitter, providing links to the website and our latest talks, press releases, and papers. We will continue to partake outreach events including 'Pint of Science', and Nature Live talks at the Natural History Museum.


d) Undergraduates: We will engage undergraduate students directly in the project by enabling hands-on laboratory expertise, a passion for scientific endeavour, and a deep knowledge of the research field. Summer projects and final year projects provide a great opportunity for advisors and students to integrate education and research beyond the classroom, advance discovery and understanding, while providing training on solving scientific problems and laboratory skills. Major findings will also be posted on the Departmental Facebook pages allowing the wider undergraduate community to maintain awareness of cutting-edge research activities that are happening in their building.


e) Training and mentoring of PDRAs: This project will enhance the career development of two named PDRAs (Wilson and Chen) as well as benefit the onward career of recently hired Faculty member and co-I Rae. PI LR and Co-I TvdF both have excellent track records in actively training and advising postdoctoral scholars. They will also help Rae to develop effective mentoring skills throughout the course of this project.


f) Increasing Women in STEM: The proposal supports two mid-career female investigators who will provide mentorship and role models for junior women in STEM subjects. We will include sections on our websites that touch on how women provide leadership in STEM subjects, from being Chief Scientist on a research cruise, to leading research teams as well as the paths we took to get here. Efforts will be made to include female undergraduates in the project through direct internships and through outreach presentations. Impact will be assessed by website traffic and event attendance.
 
Description Here I outline key Findings that are part of the ongoing research outcomes of the project:

(1) Detailed analysis of the clumped isotope ratios in deep sea corals pointed to a dual control of both temperature and biomineralisation. The results were published in GCA, and we are modifying our approach to reconstructing temperature to take account of these findings.

(2) We have now analysed the ages of more than 1900 fossil coral skeletons from the Drake Passage. The age distributions are allowing us to select samples for the major paleoclimate aims of the project. We also observe distinctive patterns of population change at different sites and for different groups of corals.

(3) We have a paper published in PNAS with our project partners. The d15N analyses analysed by PhD student Tony Wang were used to explore nutrient cycling and the impact of primary production in the Southern Ocean on global climate. A follow up paper focussing on the Holocene has now been published by Anja Studer in Nature Geoscience

(4) Ongoing research within the team is producing a new and highly resolved multi-proxy data set spanning the last deglaciation - including proxies for temperature, water mass, nutrient cycling and carbon cycling. We are working towards integrating these data to produce a combined record on a well constrained timescale. Two studies which are now well developed include (a) use of boron isotopes to show how carbon storage in the Southern Ocean changes on abrupt timescales - published in Nature by Rae et al (b) how ocean stratification links to surface ocean productivity and atmospheric CO2 - submitted to Scientific Advances. Additional papers continue to be prepared by group members.
Exploitation Route Our research is still ongoing, and we envisage further outcomes of the program as the project enters its final stages.

As a team we have been engaged in sharing the results of our work with the traditional academic audiences through talks, conferences and publications.

We have also been sharing our research outcomes through outreach activities including talks and school visits in a variety of settings. We plan to continue these activities, expanding out to include as wide an audience as possible.

As we interpret our results we will be considering how they may be used by the environmental sector. Deep water corals (and associated habitats) have potential value providing habitats for fish, biodiversity and even for natural product recovery. A new understanding of how and why deep water corals thrive and / or die out in response to environmental change has the potential to guide issues such as creation and management of Marine Protected Areas.
Sectors Environment,Culture, Heritage, Museums and Collections

URL https://bristoloceans.wordpress.com/
 
Description The data are being included in outreach talks by the team, thus our science is reaching a wide audience within the general public.
First Year Of Impact 2016
Sector Education
Impact Types Cultural,Societal

 
Description Benjamin Meaker Fellowship
Amount £2,000 (GBP)
Organisation University of Bristol 
Sector Academic/University
Country United Kingdom
Start 09/2016 
End 10/2016
 
Description International Opportunities Fund 2017 - Pump Priming
Amount £40,000 (GBP)
Funding ID NE/R005117/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 05/2018 
End 05/2020
 
Description Natural Environment Research Council
Amount £608,622 (GBP)
Funding ID NE/S001743/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 02/2019 
End 01/2022
 
Description Clumped isotopes 
Organisation Woods Hole Oceanographic Institution
Country United States 
Sector Charity/Non Profit 
PI Contribution Samples were analysed at WHOI
Collaborator Contribution The Partner is analysing the samples for clumped isotopic values.
Impact Paper lead by PhD student Spooner (http://dx.doi.org/10.1016/j.gca.2016.01.023)
Start Year 2015
 
Description Nitrogen Isotopes 
Organisation Aarhus University
Department Department of Geoscience
Country Denmark 
Sector Academic/University 
PI Contribution We selected and prepared samples for analyses and analyses were made at Princeton.
Collaborator Contribution The partner and graduate student Tony Wang (now a Post Doctoral Scholar at Caltech) analysed samples for nitrogen isotopes. In addition extended collaboration with the Princeton a group and their network have resulted in new publications in PNAS and Nature Geosciences.
Impact Publication in PNAS lead by Wang (see publications) Publication in Nature Geoscience lead by Studer (see publications)
Start Year 2015
 
Description Southern Ocean dynamics 
Organisation University of California, Los Angeles (UCLA)
Department UCLA Atmospheric and Oceanic Sciences
Country United States 
Sector Academic/University 
PI Contribution We have contributed new data and ideas based on our paleoceanographic reconstructions that have motivated a new set of modelling approaches, forming the basis of a new PhD studentship project at St Andrews in Collaboration with our colleagues in the School of Mathematics.
Collaborator Contribution Our partners have contributed significant expertise in mathematical modelling and instigated a joint PhD studentship, which they have day to day responsibility for.
Impact Not yet - it has just commenced.
Start Year 2017
 
Description Southern Ocean dynamics 
Organisation University of St Andrews
Department School of Mathematics and Statistics
Country United Kingdom 
Sector Academic/University 
PI Contribution We have contributed new data and ideas based on our paleoceanographic reconstructions that have motivated a new set of modelling approaches, forming the basis of a new PhD studentship project at St Andrews in Collaboration with our colleagues in the School of Mathematics.
Collaborator Contribution Our partners have contributed significant expertise in mathematical modelling and instigated a joint PhD studentship, which they have day to day responsibility for.
Impact Not yet - it has just commenced.
Start Year 2017
 
Description BOPP website 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Website highlighted ocean research at Bristol, linking to cruise websites, outreach videos and projects.
Year(s) Of Engagement Activity 2016,2017
URL https://bristoloceans.wordpress.com/
 
Description CPD event for Scottish Geography Teachers 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact At the Scottish Association of Geography Teachers annual conference we ran two 50 minute sessions with 15 teachers in each session. Each workshop was made up of a series of kitchen cupboard still experiments to help explain climate. Teachers will provided with the power point, worksheets and experiment instructions to be able to disseminate information to their classes.
Year(s) Of Engagement Activity 2016
 
Description Development of online resources promoting good practice when teaching climate science. These resources are linked to the 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Schools
Results and Impact The online resources are being developed by the GeoBus team over an 18 month period July 2016 -December 2017. These resources include a series of lesson plans under 4 titles:
* It's happening: Evidence of Climate Change
* It's Us: Causes of Climate Change
* It's Serious: Impact of Climate Change
* It's Solvable:Solutions to Climate Change

These resources can be downloaded and taught by teachers all over the world but are specifically linked to the Scottish and English curriculum, from March 2017 we will be able to track the downloads of resource. The assumption is that it will be educators who download the resources and will disseminate the lessons to there classes. the average class size is 20 pupils for science class and 30 for a social science class. The resources have sparked interest from teachers and international educators (AGU) who have asked for similar resources to be produced in the future.
Year(s) Of Engagement Activity 2016,2017
URL https://geobus.st-andrews.ac.uk/resources/carbon-capture-storage/
 
Description Herdman Symposium 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Undergraduate students
Results and Impact Seminar as part of the Herman Symposium organised by Undergradute Students at the University of Liverpool open to public.
Year(s) Of Engagement Activity 2020
 
Description Press Release for Science Paper 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Press Release for Science Paper 'Ocean mixing and ice-sheet control of seawater 234U/238U during the last deglaciation' from University of Bristol publicised by other outlets.

E.g.
https://www.sciencedaily.com/releases/2016/10/161007154916.htm
http://oceanleadership.org/uranium-levels-deep-sea-coral-reveal-new-insights-major-northern-ice-sheets-retreated/
Year(s) Of Engagement Activity 2016
URL http://www.bristol.ac.uk/news/2016/october/uranium-coral.html
 
Description Public talk - Boston Aquarium 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Large publich outreach talk 'The Carlson Lecture' organised by MIT at the Boston Aquarium, also live streamed and available on line.
Year(s) Of Engagement Activity 2019
URL https://www.youtube.com/watch?v=gVsv0Xn4YhQ
 
Description ROck Wow 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Rock "WOW" day is a talk-workshop held in schools through which we try to spark an interest in earth science (and science in general).
Year(s) Of Engagement Activity 2016,2017
 
Description School Careers Event 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact School Careers Event for Six form puils
Year(s) Of Engagement Activity 2017
 
Description Talk in Bristol Cafe 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Undergraduate students
Results and Impact Talk to Bristol University Sustainability Team
Year(s) Of Engagement Activity 2017
 
Description Teaching 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Other audiences
Results and Impact Inclusion of research material in undergraduate lectures- including third year 'Oceanography' and MSci level 'Tracing and Observing the Earth System'
Year(s) Of Engagement Activity 2011,2012,2013,2014,2015,2016,2017,2018,2019,2020
 
Description TedX talk, continuing views now at 1,653,960 views 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact TedX talk in 2014 was subsequently selected for upload to main TED site and now has 1.5million views. Content closely aligned with project goals. Included in submission as it continues to attract views on the internet
Year(s) Of Engagement Activity 2014
URL https://www.ted.com/talks/laura_robinson_the_secrets_i_find_on_the_mysterious_ocean_floor